<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			  /* 通用选择器 */
				* {
				     margin:0;
				}
				/* 群组选择器 */
				h1,h6,p,ul {
					 /* margin:0; */
				}
		     #item2 {
					    /* 文本粗细(体重)：加粗 */ 
				      font-weight: bold;
				 }
				 span {
					 /* 显示模式,由默认的inline变成block */
					 display: block;
			   }
				 
	      .text-msg{
					color:white;
					}
      
				.text-danger{
					background-color: red;
				}	
	     
				.text-success{
					background-color: green;
				
				}
	
	
	
	
	
		</style>
	</head>
	<body>
		 <h1>一号标题</h1>
		 <h6>六号标题</h6>
		<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Iusto sequi minima sint alias eveniet perferendis ducimus deserunt ad ea vitae eaque in autem soluta impedit deleniti necessitatibus unde explicabo dolor.</p>
		<ul>
			<li id="item1">首页</li>
			<li id="item2">学习用品</li>
			<li>私人订制</li>
		</ul>
		<hr >
		<hr > class="text-danger"
		<span class="text-danger">用户名不能为空</span>
		<span class="text-danger">密码不能为空</span>
		<span class="text-danger">两次输入的密码不一样</span>
		
		<span class="text-success">用户名可用</span>
		<span class="text-success">密码长度合法了</span>
		<span class="text-success">两次输入的密码一样了</span>
		
		
	</body>
</html>
